title: Cyclin D1, retinoblastoma and p16 protein expression in carcinoma of the gallbladder.
abstract: BACKGROUND
  Cancer of the gallbladder is a relatively rare neoplasm with a poor prognosis. The exact mechanisms of its genesis are not known and very little information is available on molecular events leading to labeling this as an orphan cancer.
  
  
  METHODS
  In this prospective case control study we evaluated the expression of p16, pRb and cyclin D1 by immunohistochemistry to study the G1-S cell-cycle check point and its possible role in gallbladder carcinogenesis. A total of 25 patients with gallbladder carcinoma (group I), 25 with cholelithiasis (group II) and 10 normal controls. were enrolled.
  
  
  RESULTS
  Cyclin D1 expression was seen in 10 (40%) patients each with carcinoma and cholelithiasis while only in 2 (20%) of the normal gallbladders but differences were not statistically significant (p value=0.488). p16 was expressed in 12% patients of carcinoma of the gallbladder and 28% of cholelithiasis, however this difference was not statistically significant (p value=0.095). Retinoblastoma protein was found to be expressed in 50% of normal gallbladders and 6 (24%) of carcinoma and 8 (32%) of gallstones. The present study failed to demonstrate any conclusive role of cyclin D1/RB/ p16 pathway in carcinoma of the gallbladder.
  
  
  CONCLUSIONS
  The positive relation observed between tumor metastasis and cyclinD1 expression and p16 with nodal metastasis suggested that higher cyclin D1/p16 expression may act as a predictive biomarker for aggressive behavior of gallbladder malignancies.
authors.affiliation: Department of Surgical Oncology and Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Vineeta
authors.initials: V
authors.lastname: Srivastava
authors.forename: Brijesh
authors.initials: B
authors.lastname: Patel
authors.forename: Mohan
authors.initials: M
authors.lastname: Kumar
authors.forename: Mridula
authors.initials: M
authors.lastname: Shukla
authors.forename: Manoj
authors.initials: M
authors.lastname: Pandey
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D016022:Case-Control Studies; D002769:Cholelithiasis / Q000473:pathology*; D019938:Cyclin D1 / Q000096:biosynthesis*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D005260:Female; D005704:Gallbladder / Q000473:pathology; D005706:Gallbladder Neoplasms / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011379:Prognosis; D011446:Prospective Studies; D016160:Retinoblastoma Protein / Q000096:biosynthesis*; D059807:S Phase Cell Cycle Checkpoints
chemical_list: D014408:Biomarkers, Tumor; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D019938:Cyclin D1